Regular Weather Conditions Research Articles

Establishing correlations between time series of wastewater parameters under extreme and regular weather conditions

Establishing correlations between time series of wastewater parameters under extreme and regular weather conditions

Effects of Irregular Climate Environment on Plant Community Diversity——BP neural network model based on gray prediction optimization

Plant communities play a vital role in the ecological environment. In order to explore the relationship between drought adaptability and the number of species in the plant community, this paper discusses the survival ability of the plant community in a drought environment by constructing a neural network model, and studies and discusses the impact of the interspecific relationship of the plant community on survival. First, we found a positive correlation among the species in community Ⅱ through multiple regression model. Second, we quantify the concept of plant community into time-series data. Under the premise of considering the interaction between species, a BP neural network model based on gray prediction optimization was established to obtain the change law of species diversity index over time under different regular weather conditions. Finally, two concepts of species number and species type are introduced. The stability of the model was tested by changing the size of the species number and exchanging the dominant species among the communities.

Forest connectivity percolation thresholds for fire spread under different weather conditions

How fuel influences fire spread at different spatial scales has been broadly studied but it is still under research. Although prior research has generally explored fuel effects at the stand scale, there is increasing recognition that forest structure and composition at the landscape scale can regulate fire size when weather conditions allow fire to have enough initial capacity to spread. Simulation models have usually been adopted to test forest landscape structure’s effect on fire activity, but we still lack empirical evidence of these effects on a broad scale and using multiple fires. In this study, we use the graph theory and the percolation theory to test the relationship between forest functional connectivity and fire size in a Mediterranean region (Catalonia, NE Spain, ~32000 km2) and under different weather conditions. Using a total sample of 554 fires that occurred between 1987 and 2019, we relate fire size with forest connectivity inside the fire perimeter, which we describe with different interpretations of forest-land cover maps and at different fire dispersal distances (10-, 100- and 2000- meters spotting capacity). Previously, fires were classified according to the weather and drought conditions in which they occurred (windy, arid or regular days, and dry or non-dry conditions) with the hypothesis that the capacity of fire to “read” the forest landscape differs according to weather variables. We found that a forest percolation threshold existed for most types of fires: forest connectivity had a positive influence on fire size until a threshold at which the landscape becomes continuous and other processes to control fire cease to have effect. This percolation threshold is about 0.40 for fires occurring under arid conditions. Under regular weather conditions, the threshold is non-existent and forest connectivity always exerts a positive effect on fire size. Notably, forest connectivity has no influence on fire size on windy- and dry-weather days. All these results are of paramount relevance for forest and landscape management aimed at reducing wildfire risk, since for fires driven by extreme weather conditions (more prone to happen in the future), landscape offers less opportunities to stop them. Researchers and managers need to identify the probability of experiencing each of the different weather types in a climate change context to boost the management of forests and landscapes in a cost-effective way.

Influence of oceanographic and meteorological events on the quantity and quality of marine debris along an estuarine gradient

The influence of three meteorological/oceanographic conditions – frontal systems (FS), high riverine discharges (HRD) and regular weather conditions (RWC) – over the quantity (Overall Abundance and Richness of types) and quality (composition and most probable source) of marine debris was assessed in sand beaches along three sectors (internal, I; median, M; and external, E) of an estuarine gradient. The highest overall abundance and richness of types were observed in HRD (I and E), while the lowest were observed in RWC (I and M). The external sector showed lowest abundance in FS. Greatest numbers of “domestic” and “sewage related debris” were observed under HRD (I > E > M). Greatest numbers of “fisheries” items were observed in HRD (I and E). For “unknown” sourced items, there was no indication of a single condition with smaller quantities (E > I = M). Results suggest that adopting oceanographical and meteorological conditions for analysis have the potential to detect temporal variations.

Influences of harvester and weather conditions on field loss and milling quality of rough rice

A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice. The main objective of this study was to evaluate the impact of harvester header, harvester type, and weather conditions on field loss and milling quality of rough rice. Four popular harvesters equipped with different headers: John Deere 9870 with header D60-S, John Deere 9860 with header D972-S, Hardy, and John Deere 9770 with stripper header were evaluated in this study. The header and total field losses of rice were evaluated for each harvester under regular, rainy and windy weather conditions. Tests were conducted in a rice field cultivated with medium grain rice, variety M206, at Grimes, CA. Total rice yield (TRY), head rice yield (HRY) and whiteness index (WI) were examined to evaluate the effect of weather conditions on milling quality. The obtained results revealed that the rice field loss was affected by harvester header and type, and weather conditions. Among the conventional headers, D60-S significantly reduced the rice loss compared to the D972-S and the Hardy. Harvesting with John Deere 9860 resulted in significant header and field loss compared to other tested harvesters. The average loss increased from 236.2 kg/hm2 and 445.2 kg/hm2 under regular condition to 711.1 kg/hm2 and 907.9 kg/hm2 under windy condition for John Deere 9870 and John Deere 9860, respectively. The corresponding loss percentages increased from 2.6% and 4.9% to 7.9% and 10.1%. HRY was significantly affected by weather condition at harvest time. However, the weather condition had no significant effect on TRY and WI. To minimize the rice field loss and obtain good milling quality, commercial rice harvesting during regular weather conditions is important. A proper combination of harvester type and header could be vital for reducing the rice loss. Keywords: rice, harvesters, field loss, weather conditions, milling quality, harvester header DOI: 10.25165/j.ijabe.20171004.2993 Citation: Khir R, Atungulu G, Ding C, Pan Z L. Influences of harvester and weather conditions on field loss and milling quality of rough rice. Int J Agric & Biol Eng, 2017; 10(4): 216–223.

Influences of harvester and weather conditions on field loss and milling quality of rough rice

A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice. The main objective of this study was to evaluate the impact of harvester header, harvester type, and weather conditions on field loss and milling quality of rough rice. Four popular harvesters equipped with different headers: John Deere 9870 with header D60-S, John Deere 9860 with header D972-S, Hardy, and John Deere 9770 with stripper header were evaluated in this study. The header and total field losses of rice were evaluated for each harvester under regular, rainy and windy weather conditions. Tests were conducted in a rice field cultivated with medium grain rice, variety M206, at Grimes, CA. Total rice yield (TRY), head rice yield (HRY) and whiteness index (WI) were examined to evaluate the effect of weather conditions on milling quality. The obtained results revealed that the rice field loss was affected by harvester header and type, and weather conditions. Among the conventional headers, D60-S significantly reduced the rice loss compared to the D972-S and the Hardy. Harvesting with John Deere 9860 resulted in significant header and field loss compared to other tested harvesters. The average loss increased from 236.2 kg/hm2 and 445.2 kg/hm2 under regular condition to 711.1 kg/hm2 and 907.9 kg/hm2 under windy condition for John Deere 9870 and John Deere 9860, respectively. The corresponding loss percentages increased from 2.6% and 4.9% to 7.9% and 10.1%. HRY was significantly affected by weather condition at harvest time. However, the weather condition had no significant effect on TRY and WI. To minimize the rice field loss and obtain good milling quality, commercial rice harvesting during regular weather conditions is important. A proper combination of harvester type and header could be vital for reducing the rice loss. Keywords: rice, harvesters, field loss, weather conditions, milling quality, harvester header DOI: 10.25165/j.ijabe.20171004.2993 Citation: Khir R, Atungulu G, Ding C, Pan Z L. Influences of harvester and weather conditions on field loss and milling quality of rough rice. Int J Agric & Biol Eng, 2017; 10(4): 216–223.

Effect of Vortex Induced Vibration on a Paired-Column Semisubmersible Platform

This paper describes a numerical study of the effect of vortex induced movement (VIM) on the hull of a paired-column semisubmersible (pc-semi) platform in relation to the column geometric properties. A computational fluid dynamics (CFD) analysis was carried out and vortex shedding was observed. The response of the square and rectangular columns hull configuration was investigated using ANSYS AQWA and the maximum amplitude was observed to be almost the same for both geometry, but it occurred at different range of reduced velocity Vr. The effect of surface wave and flow incidence angle were investigated for extreme and regular weather conditions, and it was found that VIM occurred at 2 ≤ Vr ≤ 12.

THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE ROTATIONAL SPEED OF DESICCANT WHEEL

This paper presents a study on different kinds of air conditioning systems in association to existing one to use through of the year. The system have generally desiccant wheel, evaporative cooler, heating coils and cooling coil. Mainly the system imparts all three regular weather conditions. Like hot and dry, hot and wet and cool and dry. For this the out let condition will be fixed 25 dry bulb temperature (DBT) and 50% relative humidity. In the present paper, for maintaining room condition thermodynamic simulation is being done. If rotational speed of desiccant wheel is changed, the year round air conditioning equipments change own parameter to maintain the room condition .The paper also shows the variation in supply condition of air, volume of cellulose cooling pad of evaporating cooler, temperature of cooling coil in hot and wet weather conditions with respect to rotational speed of desiccant wheel (6 to 24rph).The outlet temperature of desiccant wheel increases 52.96 to 63.28°C.The efficiency of desiccant wheel increases where as saturation efficiency of evaporative cooler decreases. The volume of cooling pad decreases from 547.99 to 439.54 cm 3 w.r.t. the rotational speed of desiccant wheel. The DBT and the specific humidity of supply air remain constant

The effect of inclement weather on ankle fracture management in an Irish trauma unit

Ireland is unfamiliar with extreme weather conditions. Such conditions occurred in winter 2009-2010 and 2010-2011, with much of the country being affected by snow and ice. We reviewed the effect that these conditions had on the treatment of ankle fractures in our trauma unit. The study period was from November until February for four consecutive years from 2008-2009 until 2011-2012. We compared two winters with extreme weather with two winters with regular weather conditions. Information from Met Eireann was compared with demographics from patient records to differentiate ice-related injuries from non-ice-related injuries. Ankle fractures were classified using the Lauge-Hansen classification. We compared waiting times in A&E, waiting times for theatre, delays relating to injury severity, and overall length of stay for both groups. We identified 44 ice-related injuries and 67 non-ice-related injuries. Ice-related injuries trended towards more severe fracture configurations using the Lauge-Hansen classification. Patients sustaining ankle injuries during inclement weather were significantly younger than patients sustaining injuries during regular weather conditions. There were no other significant differences between the two groups. Ice-related injuries trended towards a greater severity of fracture configuration. We identified no significant increase in the time to treatment or overall length of stay of patients sustaining ankle fractures during these times. Ice-related injuries did not have greater rates of complications. These results are a testament to the trauma staff in this unit who absorbed the increased workload without compromising patient care.

Effect of sewage treatment plants and diffuse pollution on the occurrence of protozoal parasites in the course of a small river

In Germany, protozoal parasites are detected frequently in surface waters. This study aims to assess the parasitological pollution in a river course and two of its tributaries under regular weather conditions. Cryptosporidium was detected in 67% of all samples. The median concentration was 4 oocysts/100l. Giardia lamblia were detected in 90% of the samples. The median concentration of G. lamblia was 22 cysts/100l and increased significantly following the river course. A statistically significant correlation was found between both parasites and the faecal indicators Clostridium perfringens and Escherichia coli. The intermittent occurrence of Cryptosporidium in the streams investigated was ascribed primarily to diffuse pollution, particularly during rainfall events. The relatively frequent detection of G. lamblia derived mainly from sewage treatment plants. The pathogen concentrations observed present a relevant public health risk as the river is used for recreational activities and agricultural purposes.

How does drought stress influence the decomposition of plant litter with contrasting quality in a grassland ecosystem?

Plant litter quality and water availability both control decomposition. The interaction of both parameters was never studied. We used a grassland site, where litter of contrasting quality, i.e. green litter (fresh leaves; high quality) and brown litter (dead leaves, which underwent senescence but which are still attached to the plant; low quality), is returned to soil. Green and brown litter were exposed in the field under regular weather and drought conditions. The objective of this study was to evaluate the effect of drought on the decomposition of both litter types. We incubated green and brown litter of three different grassland species (Lolium perenne, Festuca arundinacea and Dactylis glomerata) alone or as litter mixture (1/3 of each of the three grassland species) in litterbags for 28 weeks. Drought conditions were simulated by rainfall exclusion. After incubation, litter residues were analysed for C and nitrogen (N) content and stable isotope composition. Additionally, we determined the response of the lignin and carbohydrate signatures to the contrasting conditions. C decomposition kinetics of green and brown litter under drought conditions could be explained by two pools of contrasting turnover times. Drought decreased leaf litter C and N decomposition by more than 50% compared to regular weather conditions, mainly by strongly decreasing the decomposition rate constants. The lowest C decomposition occurred for mixtures of litter from all three grassland species. Brown litter showed on average 15% higher reduction in carbon decomposition than green litter following drought. Lignin content remained similar for green and brown litter after drought and regular weather conditions, while sugar content remained similar in green litter and decreased by 18% for brown litter under drought conditions. Our results showed different response of decomposition of litter with contrasting quality to drought. Low quality brown litter is likely to be more affected than high quality green litter. Thus, litter quality must be taken into account, when assessing the effect of drought on decomposition.

002 ANALYSIS OF 1000 CASES OF LAPAROSCOPIC DONOR NEPHRECTOMY FROM A DEVELOPING COUNTRY

How fuel influences fire spread at different spatial scales has been broadly studied but it is still under research. Although prior research has generally explored fuel effects at the stand scale, there is increasing recognition that forest structure and composition at the landscape scale can regulate fire size when weather conditions allow fire to have enough initial capacity to spread. Simulation models have usually been adopted to test forest landscape structure’s effect on fire activity, but we still lack empirical evidence of these effects on a broad scale and using multiple fires. In this study, we use the graph theory and the percolation theory to test the relationship between forest functional connectivity and fire size in a Mediterranean region (Catalonia, NE Spain, ~32000 km2) and under different weather conditions. Using a total sample of 554 fires that occurred between 1987 and 2019, we relate fire size with forest connectivity inside the fire perimeter, which we describe with different interpretations of forest-land cover maps and at different fire dispersal distances (10-, 100- and 2000- meters spotting capacity). Previously, fires were classified according to the weather and drought conditions in which they occurred (windy, arid or regular days, and dry or non-dry conditions) with the hypothesis that the capacity of fire to “read” the forest landscape differs according to weather variables. We found that a forest percolation threshold existed for most types of fires: forest connectivity had a positive influence on fire size until a threshold at which the landscape becomes continuous and other processes to control fire cease to have effect. This percolation threshold is about 0.40 for fires occurring under arid conditions. Under regular weather conditions, the threshold is non-existent and forest connectivity always exerts a positive effect on fire size. Notably, forest connectivity has no influence on fire size on windy- and dry-weather days. All these results are of paramount relevance for forest and landscape management aimed at reducing wildfire risk, since for fires driven by extreme weather conditions (more prone to happen in the future), landscape offers less opportunities to stop them. Researchers and managers need to identify the probability of experiencing each of the different weather types in a climate change context to boost the management of forests and landscapes in a cost-effective way.